In general, bedclothes refer to the bedding that contains a wadding material such as cotton, wool, goose feathers, chemical cotton or synthetic fibers. The bedclothes are bulky and quite difficult to transport or store. Furthermore, the wadding material contained in the bedclothes tends to gather moisture and become moldy, thereby giving off offensive smell. This makes it difficult to store and manage the bedclothes.
As a solution to the problems inherent in storage and management of the bedclothes, there has been proposed a bedclothes compressing-and-storing bag that compresses and stores bedclothes in a vacuum state. The bedclothes compressing-and-storing bag includes a collapsible bag body made of a synthetic resin sheet and adapted to receive bedclothes or garment and an air discharge valve attached to the bag body and used in discharging an air from the bag body.
With the bedclothes compressing-and-storing bag noted above, bedclothes or garment are received into the bag body. After closing an opening of the bag body, the internally existing air is discharged through the air discharge valve by means of a vacuum cleaner or other evacuation devices. Thus the bedclothes or garment are compressed into a reduced volume and isolated from the externally existing air. This allows the bedclothes or garment to be transported and stored with ease, while preventing infiltration of moisture or mold into the bag body.
The role played by the air discharge valve is of paramount importance in the bedclothes compressing-and-storing bag. The present inventor has filed a number of Korean patent and utility model applications regarding air discharge valves designed to readily discharge the air existing in a bag body and also to keep the bag body air-tight.
Korean Utility Model Registration No. 20-414999 discloses an air discharge valve as shown in FIG. 1. The air discharge valve includes a main body 3 attached to a vacuum storage bag 2, a support plate 4 coupled to the main body 3 and a valve body 6 fitted into an internal space 5 between the main body 3 and the support plate 4. The valve body 6 is vertically moved to open or close an air passage formed in the main body 3. The main body 3 has an annular bottom groove 3a opened upwardly and a contact protrusion 3b extending upwards within the annular bottom groove 3a. The valve body 6 has an O-ring 7 on its lower surface. The O-ring 7 is inserted into the annular bottom groove 3a and then is brought into close contact with the contact protrusion 3b, thereby providing an air-tight sealing.
With this air discharge valve, the O-ring 7 is moved up and down together with the valve body 6 to open and close the air passage formed in the main body 3. When closing the air passage, the O-ring 7 makes air-tight contact with the side walls of the annular bottom groove 3a as well as the contact protrusion 3b. 
In the air discharge valve set forth above, however, the O-ring 7 makes frictional contact with the main body 3 as it is moved up and down together with the valve body 6. For this reason, the O-ring 7 may possibly be separated and detached from the valve body 6, which in turn may destroy air-tightness.
In an effort to improve such a problem, Korean Patent No. 10-684669 discloses an air discharge valve as shown in FIG. 2. The air discharge valve includes a main body 3 attached to a vacuum storage bag 2, a cover plate 4 coupled to the main body 3 and a valve body 6 fitted into an internal space 5 between the main body 3 and the cover plate 4. The valve body 6 is vertically moved to open or close an air passage formed in the main body 3. The main body 3 has a packing-receiving groove 3-1 formed outwardly and upwardly of the air passage. A packing 8 is inserted into the packing-receiving groove 3-1 and pressed by an inner rim portion 4-1 of the cover plate 4. The valve body 6 has a stepped contact surface 6-1 that makes contact with the upper and inner surfaces of the packing 8 to provide an air-tight sealing.
With this air discharge valve, the packing 8 is fixedly secured between the main body 3 and the cover plate 4, and the valve body 6 is moved up and down with respect to the packing 8 to open and close the air passage formed in the main body 3. This prevents any inadvertent separation and detachment of the packing 8, while assuring improved air-tightness.
In the air discharge valve noted above, however, the inner rim portion 4-1 of the cover plate 4 protrudes into the internal space 5 to press the packing 8 against removal. For this reason, the inner rim portion 4-1 obstructs the flow of air in the internal space 5, consequently reducing the operability of the air discharge valve.
In addition, with the air discharge valve disclosed in the Korean patent, the valve body 6 and the air passage are all exposed to the outside. Since the valve body 6 functions merely to close the air passage, the air discharge valve suffers from reduction in air-tightness. Another problem resides in that foreign materials or moisture are introduced into the air passage, thus leading to damage, malfunction and contamination of the air discharge valve.